l carnitina 500 Now Foods L-Carnitine mg 180 Capsules : Health & Household Carnitine also helps the body use energy stores to power muscular contractions Source Naturals - L-Carnitine 500

For one cycle, yes

Various studies have been performed recently too, such as this one by the US National Library of Medicine, but there is no conclusive evidence of it working for skin lightening yet

Molecular pathways documented in preclinical research include: (1) activation of nitric oxide (NO) synthesis via L-arginine/eNOS pathway, (2) transcriptional upregulation of VEGF-A and FGF-2 favouring angiogenesis, (3) modulation of the Egr-1 early transcription factor involved in fibroblast proliferation, (4) interaction with 5-HT2A and dopaminergic receptors in some behavioural models, (5) stabilisation of endothelial function via eNOS modulation and reduction of oxidative stress (8-OH-dG, MDA)

Journal of Medicinal Chemistry

Acetyl-L-Carnitine Supplementation and the Treatment of Depressive Symptoms: A Systematic Review and Meta-Analysis